Preheat the oven to 425 degrees and prepare the ramekins. Grease five 6oz ramekins with butter and dust with flour or Toll House cocoa. Place on a baking sheet and set aside.
In a large microwave-safe bowl, melt the dark chocolate with the butter. Stir until smooth. Add La Lechera sweetened condensed milk, eggs, and vanilla. Whisk until smooth. Fold in the flour and instant coffee.
Spoon the batter evenly into the ramekins or muffin cups leaving some room at the top of the mold for the cakes to rise.
Bake in the oven for 12-14 minutes until the sides are slightly firm, but the tops still look a little soft.⏱ 14 min
Remove from the oven, and let them rest for 1 minute. Using an oven mitt, cover with a plate, invert, and turn over.
Dust the top with cocoa powder and serve immediately as is or with a scoop of ice cream for an extra decadent treat!
If you do not have ramekins, you can use a muffin tin. If using a muffin tin reduce the bake time to 8-10 minutes. To remove the cakes from the muffin tin, gently use a spoon to release the cakes and place them upside down on a plate to serve.